.223 Ackley Improved in an AR

[Rock Knocker]

Im giving some thought into getting my barrel fitted to the AI, mostly for brass life... and of course a little extra power. I plan on going out and getting $100 worth of Lapua brass and thats more than half the price of getting the barrel work done. So if the little extra money in barrel work saves that $100 worth of brass for twice as long as standard .223 it makes sence to me. And fire forming seems just like another opsticle to conquer, and it gives me something to do.

But what is the whole deal breaker for me is that ive heard once or twice that the straight walled AI cases have some problems feeding. I just heard that in general, so i figured it must be more prevelant in ARs. So i was wondering if there are a lot of feeding problems in ARs that have AI chambers. And wondering if there are any other reasons i should be warry of getting this done.

BTW... $175 job from Gander Mountain, not wild about trusting Gander Mountain with something like this, but i havent found anyone else that does this work in MN, and i havent heard any horror stories about Gander i just tend to go with the little guys whenever possible. SO any pointers there would be greatly appreciated also.

 

[K0na_stinky]

I have a few questions. Does 223 AI brass really last 2 times as long? Is the brass that lasts 2 times as long fire formed?

 

[cmillard]

i think that you are better off buying unfired Lake City brass for this rifle. plus, dont be surprised if you have some feeding issues with the AI version since there is less body taper. extraction wise you should be fine. i would assume you will be shooting a 7 or 8 twist?

 

[jonbearman]

Go to 6mmar.com and see what they have accomplished and made to feed.They may have ideas for you to followup on.Clarke guns(jerry miculek) does ar rifles as well as a bunch of others out there.Try googling gunsmiths that work on ar's.I think even with little body taper it will work with the m4 barrel extension(better feed ramps).

 

[jonbearman]

Go to: AR-15 Rifle vault,it has listings to boggle the mind.Secondly go to: AR-15.com, and whiteoak precision(call them for custom work, Hofmeister custom shop.Try this and tap into the imfo they offer,dont just read but call them for all custom work and talk to dave kiff at ptg for your custom reamer.

 

[Rock Knocker]

Thanks for the info. Im actually shooting a 1-9" twist 24" ER shaw bull barrel. Im going for accuracy(without spending too much money, ive already looked up just buying an AI barrel.) Dispite some of the stuff ive heard about ER shaw barrels, I have no reason to not like mine. i just started hand loading, my best group so far has been .916" at 150 yards, but this was my first group of hand loads and i was laying on the ground using my hunting pack as a rest. .916 was actually with one wondering bullet, so my .36" group may be a better representation esspecially if i had a bench and better rest. Im shooting 69gr. sierra MKs right now but will be trying Hornady 68gr. bthp and 75gr. Amaxs.

Im going to be looking up what you guys have posted. Thanks for the pointers. I really only looked up Minnesota gun shops, so i didnt have to ship anything out, but i may reconsider.

 

[Klong]

Rock Knocker, my opinion is don't waste your time, barrel (fireforming), and money. The brass failure out of my 6 or 7 AR's is due to primer pockets loosening up after 6 to 8 firings by me using once fired Lake City brass. I have shot Lapua 223 brass and primers loosen the same. I don't think 223 AI will be that different from the standard 223.

 

[Rock Knocker]

So what you're saying Klong is that my primer pockets are most likely to go bad in ether version of the 223 before anything else despite excelently low brass stretching in the AI?

very good point, and exactly the kind of info i was looking for.

 

[ReedG]

Hi Rock ... not sure about the AR-15 platform, but I have a Savage Model 12 with a Pac-Nor .223 AI barrel that I have 1,200 rounds through. It still shoots tiny little groups with several loads. I have IMI, Lapua and Winchester brass, some of which have been loaded more than 15 times, and have never had a single primer pocket problem. By the way, mine is 1:14 twist and goes "ballistic" over 40-gr. Vmax's.

This brass was all fire-formed direct from .223 Rem. without a problem of any kind. In fact, the fire-form loads were as accurate as the AI loads. The primer pockets were all cut with K&M tool and all necks were turned to .012" for consistency.

I anneal them after each 4-5 loadings and cannot tell any difference from new brass. I prefer the Lapua brass, but it makes very compressed loads when using Varget so I opt to the IMI or Winchester for that. I check them for length after every firing and trim to 1.750 when they exceed 1.760 in length; maybe two or three times so far.

In my experience, the .223 AI is not the world beater that some claim it is and it's not the match of a 22BR or 22-250. What it is, though, is a neat cartridge that is measurably better than the .223 parent cartridge, easy to load, and the brass does last longer because it doesn't flow as much. Go for it, and enjoy!

 

[jonbearman]

I have gotten over 20 handloads out of the last of my norinco .223 brass,I have had a few necks split here and there. But really if klong is losing brass so easily from blown primer pockets,the loads must be a bit on the warm side.The ar shouldnt be fired with hot loads because they dont shoot any better.I would load my ackley brass at normal pressure's to not beat up the bolt carrier.

 

[15Tango]

I wanted to do the same thing but when I completed my 24" upper in standard .223 and was hitting 3015 FPS with a 75 Amax I decided I didn't need to go any faster. I'm not having pockets loosen up on me either.

Wayne

 

[Rock Knocker]

Reed thats exactly the optimism i want to have, and probly am going to be saying once i get this done(which im pretty sure i am.)

And its good to hear Tango is getting such impressive velocities with a heavy bullet. Ive had a hard time finding any velocity data from 24" ARs, everythings a bolt gun or somthing like a 16" AR.

I really want to be getting really hot .223 performance from an AI that i am not pushing the litmits on. But once again feeding reliability is pretty much on the top of my list of concerns.

 

[pdog2225]

Primer pocket issure has been mentioned. So I would like to add that don't rely on the primer pocket to give you pressure indications. The straight side wall of the case grips the chamber wall much better and reduces the rearward bolt thrust. You will exceed the safe pressure limits before the primer pocket shows it.

In my RRA 24" barrel (8T) the 69smk using AA2520 with 25.5 to 26.0grs loaded to mag length do 2944fps avg. I have shot several 2.5" groups at 550yds. Clay pidgeons dont stand a chance...

 

[jpretle]

I've pushed several thousand rounds thru a 223AI bbl in an AR 15, all w/o a hitch, what so ever. I will say, out of 7 different magazines, only one would not feed the AI case. Your brass will not last longer if you go over pressure, however. Fire forming in rapid fire, seems to be just accurate as using fire formed rounds.

 

[ReedG]

Rock, I'm going to be following the thread with interest.

1. Want to see how the sharp shoulder on the AI feeds in the AR

2. Not sure of the mag. length on the AR and am thinking bullets like the 75 Amax must have to be seated well down into the case and chew up a lot of powder capacity.

3. I've never seen 75 Amax's at anywhere near the speeds talked about here. Seems it would take more powder than will fit in the case with the long bullet seated. In my shooting with 75 Amax in a Savage 12 in standard .223, I have never seen more than 2,820 with some "hot" loads. Even with 69 SMK's and "way too much BL-C" I've never broken 3,000 fps. I'm probably too "chicken"!

4. Sure signs of pressure to me are harder extraction, flattened primers or cupped firing pin marks. Not sure what kind of "physics" would happen during combustion and burn that would enlarge a primer pocket as they are in the thickest and heaviest part of the case and it seems something else would let go before the primer pocket enlarged. Just my thoughts.

 

[Rock Knocker]

Ok. i honestly got pretty much all the information i was hoping to, BUT of course more would be great.

Honestly, this may take a little time to get done. As much as i want it, im not going to spend the money on it for at least another month. I just bought an NRA life membership, and plan on spending $300 more to homefully get into a local sportsmans club. But after i hopefully get excepted to the club it will be on the top of my list of things to throw money at.

And also i have been interested in the whole "max OAL to fit in AR magazines" thing, ive heard of people removing some of the front of standard AR mags just enough to let the tips of the stagered rounds travel up and down without catching. THIS IS ALL JUST THROUGH THE GRAPEVINE kind of thing, but im interested in it. Of course it wouldnt be in a full 30rd mag. if i were to experement with it i would start out with a 10 rnd mag and take just enough to fit 5 or so extra long rounds in it.

Thanks for all the help and keep the discussions flowing.